Quiz: Inheritance and Polymorphism

5 questionsNo time limitPass: 60%+10 XP on first pass

Reuse code with extends, call the parent with super, override methods, and understand runtime polymorphism (dynamic dispatch), overloading vs overriding and the final keyword.

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Question 1

What does this print?

class A { String who() { return "A"; } }
class B extends A { String who() { return "B"; } }
public class Main {
    public static void main(String[] args) {
        A obj = new B();
        System.out.println(obj.who());
    }
}

ABABError

Question 2
Where must super(...) appear in a constructor?
AnywhereAs the first statementAs the last statementOnly in the parent class
Question 3
Overriding is an example of:
Compile-time polymorphismRuntime polymorphismEncapsulationAbstraction only
Question 4
Which class can't be extended?
ObjectStringArrayListException
Question 5
How many classes can a Java class directly extend?
OneTwoUnlimitedNone